Polypropylene fabric has achieved commercial acceptance for decorative applications such as upholstery because of its soil resistance and other desirable properties. Backcoatings are commonly applied to aid the fabric in retaining its size, shape, and integrity in service. A "backcoat" is a polymer layer confined to one surface of the treated fabric.
Polypropylene fabrics are customarily backcoated with aqueous-based dispersions or emulsions of acrylic-type polymers. A disadvantage of aqueous-based systems is that polypropylene is temperature sensitive in comparison to other commercial fibers. Polypropylene fabric softens at about 150.degree. C. and its highest recommended drying temperature is about 122.degree. C. As a consequence of the limited degree of heat which may be applied to accelerate water vaporization, the drying of aqueous-base applied backcoating on polypropylene is a relatively slow procedure.
Polypropylene is known to deform or dissolve in chlorinated solvents, particularly when these solvents are employed at elevated temperatures.